1. Field of the Invention
The present invention relates to a slider mechanism for portable communication terminals providing a smooth operation and an improved durability.
2. Background of the Related Art
Recently, as portable wireless terminals have been increasingly popularized, users need additional functions to accommodate their tastes even in opening and closing operations of the terminal, along with its inherent functions of wireless communications.
In response to these needs, portable terminals have developed into a general bar type, flip type, flip-up type, folder type, and the like. In recent years, the folder type has been used most widely.
This is because the folder type terminal has a space enough to adopt a wide LCD module as the display device and can be held in a half-folded state to thereby provide a good portability, as compared with other type terminals.
On the other hand, a slider type terminal has been introduced, which can be equipped with an LCD module display device having a similar size to the folder type. Simultaneously, the slider type can contribute to miniaturization of portable terminals.
This slider type terminal is structured such that a sub-body corresponding to a cover is slidably opened and closed on a main body, thereby providing additional advantages of slidably opening and closing, while maintaining advantages of the existing folder type terminal.
For example, Korean Utility Model Application No. 2003-0000136 discloses a slider-type portable wireless terminal.
The terminal disclosed in the above application includes a guide means for guiding a sub-body on a main body and at least one resilient means installed between the sub-body and the main body such that its resilient force can be exerted in opening or closing direction with respect to a certain sliding point of the sub-body. In addition, when the sub-body is completely opened and closed, it can remain in its opened or closed state due to the resilient means, without any separate stopper.
The resilient means employs a torsion spring, one end of which is fixed to the main body and the other end thereof is fixed to the sub-body.
In this terminal, one end of the torsion spring is fixed to the main body and the other end thereof is fixed to the sub-body, and thus the resiliency of the torsion spring is exerted over the whole moving distance of the sub-body. Thus, the torsion spring is compressed and stretched repeatedly over a wide range of amplitude. Therefore, the torsion spring expandable over a wide length is used, but this torsion spring has a smaller resilient force. In order to compensate for the deficient resilient force, two torsion springs are employed.
However the torsion spring is deformed in a wide range inherently and easily degraded due to fatigue caused by repeated operations. Thus, the torsion spring comes to lose its normal function or leads to a failure within a shorter period of time. Accordingly, the conventional slider type apparatus uses two torsion springs, which results in a complicated and difficult assembling process and a shortened service life.